1. Technical Field
Embodiments described herein are related to analog to digital conversion (ADC), digital to analog conversion (DAC), and compression techniques for ADC/DAC.
2. Description of the Related Art
Various types of electronic systems include sensors that detect “real world” information and provide analog signals to the electronic systems representing the information. For example, temperature sensors can detect temperature in the system and/or the surrounding environment. Accelerometers can detect motion of the system through physical space. Any set of sensors can be used. Similarly, various actuators can be provided for the electronic system to interact with its environment. Actuators can include user interface devices (displays, lights, sound, etc.). Actuators can also include electrical control devices. Actuators can also include physical devices such as motors, levers, physical switches, etc.
The signals sensed by the sensors and the control data for the actuators is often analog in nature when sensed by the sensor or applied to the actuator. However, much of the electronic system is often digital. Accordingly, ADCs and DACs can be provided to convert the analog-sensed data to digital data and the digital control data to analog data. The ADCs generally quantize the analog data to one of a set of digital values, thus outputting a discrete sequence of samples of the analog signal at a specified sample rate. The DACs generally receive a discrete sequence of samples and generate a corresponding analog signal, implementing some form of interpolation to fill in data between the sample times to generate a continuous-time analog signal.
A given ADC or DAC implements a sample rate and samples are taken and transmitted at the sample rate regardless of the nature of the signal being sampled. Some signals are slow-changing compared to the sample rate, and thus redundant data is often transmitted from sample to sample. In other cases, a signal can be fast-changing at times, thus requiring a high sample rate, but can be slow-changing at other times. Power is consumed unnecessarily to transmit redundant data.